The effects of ketamine and classic hallucinogens on neurotrophic and inflammatory markers in unipolar treatment-resistant depression: a systematic review of clinical trials

Interactive Effects of Ayahuasca and Cannabidiol in Social Cognition in Healthy Volunteers

“…While investigating this subject after this trial, we recently published a systematic review of clinical trials regarding changes in inflammatory and neuroplastic biomarkers after psychedelic and ketamine administration to treatment-resistant depressed patients. 91 We found many conflicting results regarding the quantification of these substances concerning hallucinogen's effects. We concluded that trials with small samples (as the current investigation) would likely keep failing to find corroborating results in this regard.…”

“…The need for more trials with more extensive samples and better statistical power is evident to arrive confidently at any robust conclusion if biomarkers can be used as objective measures to assess the effects of psychedelics. 91 Also, regarding this subject, the most evident limitation of this trial is the lack of a bigger sample size. Our initial plan was to acquire at least 30 volunteers, but the COVID-19 pandemic lockdown resulted in an unscheduled early termination of the trial.…”

Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant

“…On one hand, most common AEs reported were gastrointestinal malaise, nausea, vomiting, headaches, and mild-to-moderate transient increases in heart rate and blood pressure [ 74 ]. These AEs were all expected and known to occur with ayahuasca and other psychedelic administration such as LSD and psilocybin [ 74 , 75 ]. On the other hand, there were more clinically significant reports of anxiety, confusion, emotional distress, depersonalization, and dysphoric state manifestations after ayahuasca administration, although these are much less common.…”

“…Furthermore, with the current published data it is very challenging to determine the optimal DMT to β-carboline ratio and dosages that maximize the therapeutic effects while also minimizing the occurrence of AEs. This and other challenges associated with standardized ayahuasca medicinal use (and other psychedelics) go beyond the main focus of this article and have been thoroughly discussed elsewhere [ 74 , 75 , 76 , 87 ] .…”

“…Reductions in the levels of such biomarkers are related to reductions in the inflammatory response and are hypothesized to be beneficial for depressed patients, especially those with an augmented inflammatory state [ 235 , 236 ]. Nevertheless, these and other inflammatory biomarkers have not yet been found to be reliable as indicators of response to rapid-acting antidepressants (such as psychedelics and ketamine), and the mechanism by which ayahuasca modulates their levels is not fully understood [ 75 , 237 ]. In fact, all these ayahuasca interactions have not been thoroughly investigated and it is yet to be shown how much they contribute to the psychoactive and possible therapeutic effects of ayahuasca in humans.…”